1. Field of the Invention
The invention relates generally to molds, and, more specifically, to adjustable mold surfaces for casting eyeglass lenses.
2. Background of the Technology
The United Nations and other organizations have estimated that at least one billion people in the world require corrective lenses but do not have access to them. This unmet need arises, in part, from the cost of lens-manufacturing laboratories and distribution. For example, the typical lens-manufacturing facility maintains separate, expensive molds for each of a wide range of possible optical lens prescriptions.
One proposed solution to this problem is the use of a single adjustable lens. In other words, the optical characteristics of each lens can be varied after manufacturing. A pair of adjustable lenses can be integrated into an eyeglass frame to provide a wide range of sight correction. However, drawbacks of this approach include increases in the overall cost of eyeglasses, and added complexity. In addition, this approach does not generally cover the entire prescriptive range.
There is also a similar general need for apparatuses and methods for forming other items from molds, in which easily adjustable mold variation can be made.